Get UISlider Value from different view.

Yves · 08-13-2010, 02:57 PM

Hey guys.
Can anyone tell me a simple way on how to get a slider value from view A into view B. Please provide some code. Thanks to anyone who attempts to answer my question!

Ladd · 08-13-2010, 04:13 PM

Quote:

Originally Posted by Yves

Hey guys.
Can anyone tell me a simple way on how to get a slider value from view A into view B. Please provide some code. Thanks to anyone who attempts to answer my question!

Does View B launch view A? (Modally or push onto stack?)

See this answer of mine which may be similar... It is about popovers on iPad but the concepts apply.
https://devforums.apple.com/thread/63458?tstart=50

Yves · 08-13-2010, 04:29 PM

Hey, thanks so much for your reply. So up to now i have had 2 different .h view controllers with 2 xib's. I used the info button to switch between them. In the second view i want to have volume control sliders that will set the volume of the music in the first view. So i would i have do this data sharing thing which my brain wont get.Now I have read about subviews.Would creating a subview solve the problem? And if so, how do i create a subview?
Thanks again.

Ladd · 08-13-2010, 04:31 PM

Quote:

Originally Posted by Yves

Hey, thanks so much for your reply. So up to now i have had 2 different .h view controllers with 2 xib's. I used the info button to switch between them. In the second view i want to have volume control sliders that will set the volume of the music in the first view. So i would i have do this data sharing thing which my brain wont get.Now I have read about subviews.Would creating a subview solve the problem? And if so, how do i create a subview?
Thanks again.

So you are using the Utility App template?

And no... SubView is not the answer IMHO...

Yves · 08-13-2010, 04:34 PM

Nope its a view based application

.

Ladd · 08-13-2010, 04:42 PM

Quote:

Originally Posted by Yves

Nope its a view based application

.

Well... How are you bringing the second view up? Modally? Animated transition?

When the info button is clicked you bring up that next view. Make the view that HAS the info button the delegate of the next one. When the slider changes call the procedure back in the first view and change the volume... You can pass the slider value back in that procedure.. (If you look at the code posted it should make sense...)

Like:

Code:

@protocol AddColorViewControllerDelegate
- (void)addDisplayViewControllerDidFinish:(AddColorViewController *)controller:(NSString *)YvesSliderVariable;
@end

Code:

[self.delegate addDisplayViewControllerDidFinish:self:sliderValue];

Hope that helps some...

Yves · 08-13-2010, 04:53 PM

Overkill m8. So the first code u posted sets View A as the delegate of View B. Then the next code you posted is how u callback the value while in View A from View B? Sorry im a bloody beginner and thanks a ton for your patience.

Yves · 08-13-2010, 04:55 PM

Oh btw its an animated transition. Also where do i place the @protocol in my code? in the header file of the first view controller?

Ladd · 08-13-2010, 04:59 PM

It might make more sense if you try this:

Create a new project from the Utility App template.

Place this statement n the following procedures:
NSLog(@"Entering >>> %s", __PRETTY_FUNCTION__);

MainViewController.m:

Code:

- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller
- (IBAction)showInfo:(id)sender

FlipSideViewController.m

Code:

- (IBAction)done:(id)sender

Now go back and forth... You will see that the procedure in Main gets called when FlipSide Done is clicked... Pass what ever you want to that procedure.

You can also pass things to FlipSide Like this:

Code:

FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideView" bundle:nil];
controller.delegate = self;
controller.YvesFlipSideVariable = "@Sweet" //Needs to be declared in Flip and I know the Capital Y is not convention... Making a point!

This is a recommend approach by Apple. (see my links in previous post reference)

Ladd

Ladd · 08-13-2010, 05:00 PM

Quote:

Originally Posted by Yves

Oh btw its an animated transition. Also where do i place the @protocol in my code? in the header file of the first view controller?

Study the FlipSideViewController and MainViewController .h files in the template. The lightbulb WILL go off...

Yves · 08-13-2010, 05:07 PM

Ok Master i shall report back to you (even if u don't care

) once i succeed!

Ladd · 08-13-2010, 05:13 PM

Quote:

Originally Posted by Yves

Ok Master i shall report back to you (even if u don't care

) once i succeed!

Cracking Up... I'm no master... Maybe a belt or two above white or yellow or whatever.

It took a lot of patience, trial and ERROR before It made sense to me... Now it does and it works well.

Let me know if does for you. I would like to hear back.

Good luck with it!!!

Ladd

Ladd · 08-13-2010, 05:29 PM

Yves... You a Kiwi by chance?

Yves · 08-13-2010, 06:40 PM

LOL A Kiwi? as in the fruit? I don't know...Im on my 15th attempt right now, so yes i'm actually beginning to wonder myself if i am in fact a kiwi. Wanna eat me-----my life is not worth living anymore

?

Ladd · 08-13-2010, 06:52 PM

Quote:

Originally Posted by Yves

LOL A Kiwi? as in the fruit? I don't know...Im on my 15th attempt right now, so yes i'm actually beginning to wonder myself if i am in fact a kiwi. Wanna eat me-----my life is not worth living anymore

?

Cracking Up again... No a New Zealander. (m8, Bloody - Hadn't heard that much since my Kiwi friends)

Still laughing!!!

Yves · 08-13-2010, 06:57 PM

nah lol, it comes from all the video games i have played

.

stoicjustice · 08-13-2010, 06:59 PM

You could always save the UISlider value as an NSUserDefaults variable. For example, wherever your slider is, put in this code:

Code:

 NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:sliderValue forKey:"slider"];

sliderValue is obviously an NSString or NSInteger for your slider.value.

Then, in whatever view of your application that you want to call that variable back, just insert the code:

Code:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *newValue = [[NSString alloc]init];
newValue = [defaults stringForKey:"slider"];

That should work. I have found that NSUserDefaults is very convenient for data persistence throughout an application.

NOTE: If for some reason you decide to save your slider value as an Integer instead of a string, make sure to use 'integerForKey' instead of 'stringForKey'. Also, make sure to release those new strings you allocate - be a good memory citizen.

Yves · 08-13-2010, 07:03 PM

Master Ladd dont worry i am still loyal to you, but i will have attempt stoicejustices wise approach to this problem.

Yves · 08-13-2010, 07:13 PM

Quote:

Originally Posted by stoicjustice

You could always save the UISlider value as an NSUserDefaults variable. For example, wherever your slider is, put in this code:

Code:

 NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:sliderValue forKey:"slider"];

sliderValue is obviously an NSString or NSInteger for your slider.value.

Then, in whatever view of your application that you want to call that variable back, just insert the code:

Code:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *newValue = [[NSString alloc]init];
newValue = [defaults stringForKey:"slider"];

That should work. I have found that NSUserDefaults is very convenient for data persistence throughout an application.

NOTE: If for some reason you decide to save your slider value as an Integer instead of a string, make sure to use 'integerForKey' instead of 'stringForKey'. Also, make sure to release those new strings you allocate - be a good memory citizen.

Thnx alot.
So i put the NSUserDefaults in my IBAction for the slider and it gives me error message my not respond to set object stringforkey and when i interact with the slider the app crashes.
please help me and thnx again.

Ladd · 08-13-2010, 07:13 PM

Quote:

Originally Posted by Yves

Master Ladd dont worry i am still loyal to you, but i will have attempt stoicejustices wise approach to this problem.

LOL... No worries (<<< Kiwi Friends remember?) I don't have all the answers.

But

Code:

in whatever view of your application that you want to call that variable back

Means your Volume slider won't register your volume changes until you return to the view. Based on your OP you want that to happen kinda "live"... Right?

Call the delegate method as it changes and it will/can. Maybe add a little delay to smooth it out... Dunno

And the below is from other code... But you should get the jist.

Code:

- (IBAction)sliderChanged:(id)sender
{
	//NSLog(@"Entering >>> %s", __PRETTY_FUNCTION__);
	
	UISlider* usedSlider = (UISlider *)sender;
	
	float answer = 0.0;
	int quarters = 0.0;
	
	
	if (usedSlider.value < 0.25) {
		answer = 0.10;
	}
	else {
		quarters = (int)(usedSlider.value * 4 + 0.25);
		answer = quarters * 0.25;
	}

	
	
	//quarters = (int)(usedSlider.value * 4 + 0.25);
	//answer = quarters * 0.25;
	
	
	if(usedSlider == speedSlider)
	{
		//NSLog(@"It is the speedSlider slider");		
		
		self.speedTextField.text = [NSString stringWithFormat:@"%.2f", answer];
		self.speed = [NSString stringWithFormat:@"%.2f", answer];	
		
	}
	
	[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(callMyDelegate) object:nil];
	[self performSelector:@selector(callMyDelegate) withObject:nil afterDelay:.2];
	
	
}



- (void)callMyDelegate
{
	//NSLog(@"Entering >>> %s", __PRETTY_FUNCTION__);		
	[self.delegate didFinish:self:speed];
}

It is all fun learning...

Ladd

stoicjustice · 08-13-2010, 07:15 PM

Could you post the code for the 2 places you are trying to utilize the code? (Both where you are saving it and where you are loading it)

stoicjustice · 08-13-2010, 07:18 PM

Quote:

Originally Posted by Ladd

LOL... No worries (<<< Kiwi Friends remember?) I don't have all the answers.

But

Code:

in whatever view of your application that you want to call that variable back

Means your Volume slider won't register your volume changes until you return to the view. Based on your OP you want that to happen kinda "live"... Right?

Call the delegate method as it changes and it will/can. Maybe add a little delay to smooth it out... Dunno

Code:

- (IBAction)sliderChanged:(id)sender
{
	//NSLog(@"Entering >>> %s", __PRETTY_FUNCTION__);
	
	UISlider* usedSlider = (UISlider *)sender;
	
	float answer = 0.0;
	int quarters = 0.0;
	
	
	if (usedSlider.value < 0.25) {
		answer = 0.10;
	}
	else {
		quarters = (int)(usedSlider.value * 4 + 0.25);
		answer = quarters * 0.25;
	}

	
	
	//quarters = (int)(usedSlider.value * 4 + 0.25);
	//answer = quarters * 0.25;
	
	
	if(usedSlider == speedSlider)
	{
		//NSLog(@"It is the speedSlider slider");		
		
		self.speedTextField.text = [NSString stringWithFormat:@"%.2f", answer];
		self.speed = [NSString stringWithFormat:@"%.2f", answer];	
		
	}
	
	[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(callMyDelegate) object:nil];
	[self performSelector:@selector(callMyDelegate) withObject:nil afterDelay:.2];
	
	
}



- (void)callMyDelegate
{
	//NSLog(@"Entering >>> %s", __PRETTY_FUNCTION__);		
	[self.delegate didFinish:self:speed];
}

It is all fun learning...

Ladd

It should be fairly instantaneous if he adds:

Code:

[defaults synchronize];

to the saving code and then loads it in the 'viewDidLoad' portion of whatever view he is transferring it to.

Yves · 08-13-2010, 07:26 PM

Ok so from the beginning i am making a drum app and when i click the info button it changes views and then from that view i want to control the volume for each drum. It dose not have to be activated until i change view again. Also i would like it to stay that way so next time when i change view the slider are where i left them.

Ok so if want me to post code i don't really have any....My flipsideview is still empty. All i did so far was create a practice app and i connected an IBOutlet to a slider and an IBAction changevalue. So i would be incredibly thankful if you could baby-feed me what i have to do.

Yves · 08-13-2010, 07:29 PM

Sorry for my grammatical retardation, its to 2:30am where i live.

Ladd · 08-13-2010, 07:30 PM

Quote:

Originally Posted by stoicjustice

It should be fairly instantaneous if he adds:

Code:

[defaults synchronize];

to the saving code and then loads it in the 'viewDidLoad' portion of whatever view he is transferring it to.

But viewDidLoad will only be called once. viewWillAppear will be called every time the view is shown. (in most instances... There are exceptions)

As I said. He wants a slider to control volume. That means he needs the changes sent to the "calling" view pretty much in real time. You can't wait for viewWillAppear. (and it won't be called in all circumstances)

Try both approaches...

Multiple options are always good. And it is nice that people contribute to help.

The delegate method is what Apple is pushing. And it works. Beautifully.